Shimano 105

Aim said:

Anyboby had problems with the Shimano 105 gears on the Giant Defy 1?

When i'm in the smaller ring at the front I can't use the three smallest gears at the back as the the chain rubs against the front bigger ring.

I've gone back to the bike shop and they have said there is nothing they can do and is a fault with the Shimano 105 gears.

Return it. Its a nice bike it should shift smoooth. They'd have to pick me up off the floor after a comment like that. :eek:

The front derailleur likely needs to have its limits set properly. Take it back, and have them do it. If they can't do it or won't, go somewhere else. It's something that takes all of a second or two to accomplish.

Aim said:

Anyboby had problems with the Shimano 105 gears on the Giant Defy 1?

When i'm in the smaller ring at the front I can't use the three smallest gears at the back as the the chain rubs against the front bigger ring.

I've gone back to the bike shop and they have said there is nothing they can do and is a fault with the Shimano 105 gears.

Tickling the big ring, not the front derailleur?

It is NORMAL. Lots of cogs(farther to the right of the bike) in back plus pickup pins and ramps on the big ring, the angle is pretty severe. Add a shortish wheelbase and you see the chain tickling the big ring when in smaller sized cogs. Shift into the big ring and up a few on the cogset, same gear ratio.

Peter@vecchios said:

Tickling the big ring, not the front derailleur?

It is NORMAL. Lots of cogs(farther to the right of the bike) in back plus pickup pins and ramps on the big ring, the angle is pretty severe. Add a shortish wheelbase and you see the chain tickling the big ring when in smaller sized cogs. Shift into the big ring and up a few on the cogset, same gear ratio.

I've seen this more often on triples with short chainstays, when using the smallest ring. Problem is not the derailleur but the chain line. You might try cheating this a little by using a shim behind the right BB bearing to push the chainrings out a bit.

You won't have a textbook perfect chain line anymore, which is why I call it a cheat. Also, you will sacrifice some performance when cross-chaining the other way.

Check it yourself and then see how easy it all is. Just read all the instructions first.

http://bike.shimano.com/publish/content/global_cycle/en/us/index/tech_support/tech_tips.download.-Par50lparsys-0027-downloadFile.html/03)%20Front%20Derailleur%20Installation.pdf

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